Transport chains
Transport chains represent a network protocol stack that is used for I/O operations within an application server environment. Transport chains are part of the channel framework function that provides a common networking service for all components, including the service integration bus component of IBM service integration technologies, WebSphere Secure Caching Proxy, and the high availability manager core group bridge service.
A transport chain consists of one or more types of channels, each of which supports a different type of I/O protocol, such as TCP, DCS or HTTP. Network ports can be shared among all of the channels within a chain. The channel framework function automatically distributes a request arriving on that port to the correct I/O protocol channel for processing.
The transport chain configuration settings determine which I/O protocols are supported for that chain. Following are some of the more common types of channels. Custom channels that support requirements unique to a particular customer or environment can also be added to a transport chain.
- TCP channel
- Used to provide client applications with persistent connections within a LAN. When configuring a TCP channel, one can specify a list of IP addresses that are allowed to make inbound connections and a list of IP addresses that are not allowed to make inbound connections. We can also specify the thread pool that this channel uses, which allows you to segregate work by the port that the application server is listening on.
- HTTP channel
- Used to enable communication with remote servers. It implements the HTTP 1.0 and 1.1 standards and is used by other channels, such as the Web container channel, to server HTTP requests and to send HTTP specific information to servlets expecting this type of information.
- HTTP Tunnel channel
- Used to provide client applications with persistent HTTP connections to remote hosts that are either blocked by firewalls or require an HTTP proxy server (including authentication) or both. An HTTP Tunnel channel enables the exchange of application data in the body of an HTTP request or response that is sent to or received from a remote server. An HTTP Tunnel channel also enables client-side applications to poll the remote host and to use HTTP requests to either send data from the client or to receive data from an application server. In either case, neither the client nor the application server is aware that HTTP is being used to exchange the data.
- Web container channel
- Used to create a bridge in the transport chain between an HTTP inbound channel and a servlet and JSP engine.
- DCS channel
- Used by the core group bridge service, the data replication service, and the high availability manger to transfer data, objects, or events among application servers.
- MQ channel
- Used in combination with other channels, such as a TCP channel, within the confines of WebSphere MQ support to facilitate communications between a WebSphere System Integration Bus and a WebSphere MQ client or queue manager.
- JFAP channel
- Used by the Java Message Service (JMS) server to create connections to JMS resources on a service integration bus.
- SSL channel
- Used to associate an SSL configuration repertoire with the transport chain. This channel is only available when SSL support is enabled for the transport chain. An SSL configuration repertoire is defined in the administrative console, under security, on the SSL configuration repertoires > SSL configuration repertoires page.
Related Tasks
Administering application servers
See Also
HTTP tunnel transport channel settings
HTTP transport channel settings
TCP transport channel settings
DCS transport channel settings
Web container transport channel settings
Repertoire settings